Create an entry to a database using post request (mongoose, mongoDB, node express)

So in the last article, we learnt about how to set up a database schema:

const mongoose = require('mongoose')

// creates a table with name, email, password column
const userSchema = mongoose.schema({
	name: String
    email: String
    password: String
})

// create a database model of userSchema, and call that model 'User'.
const User = mongoose.model('User', userSchema);

module.exports = { User }

 

and also about POST request in another article.

 

Assuming you have a code in index.js that imports User database model and connects to the mongo db:

const { User } = require('./models/User') // get User database model

//connect to mongoDB
const mongoose = require('mongoose')
mongoose.connect(someKey, {...})

We can do app.post() to register the behaviour of router at /register route.

A very basic structure would be this:

app.post('/register',(req,res)=>{
	const user = new User(req.body)
    user.save()
})

new User(req.body) creates an instance of schema, or a row that follows the database schema. Note that User is basically a class or 'model' that allows manipulation of schema (like creating an entry, updating it etc) easier. So user.save() is using a default method of that class to save the row made from request body to the mongodb database. But we want to also put a behaviour that if there's an error, the response of the request will have something in it that will notify the client about it.

(err, userInfo)=>{
	if(err) return res.json({success: false, err})
    return res.status(200).json({
    	success: true
    })
}

is exactly what does this. All in all, the following will be the code that registers a row to the mongodb database, where the data of that row comes from the request body of someone's POST request to /register route.

app.post('/register',(req,res)=>{
    const user = new User(req.body)
    user.save((err, userInfo)=>{
        if(err) return res.json({ success: false, err })
        return res.status(200).json({
            success: true
        })
    })
})